Here's one that's been used for a while:
CONSENT FOR MINOR CHILDREN TO TRAVEL
Date:_____________________
I (we):_____________________________________________ _________________
authorize my/our minor child(ren):_______________________________________ ____
to travel to:_________________________________ on:_________________________
aboard Airline/Flight Number:________________________________________
and/or Cruise Ship:_____________________________________________ with:
__________________________________________________ __________. Their expected
date of return is _______________________.
In addition, I (we) authorize:______________________________________ to consent
to any necessary routine or emergency medical treatment during the aforementioned trip.
Signed:_________________________________ (Parent)
Signed:_________________________________ (Parent)
Address:________________________________________
_______________________________________________
Telephone:______________________________________
Sworn to and signed before me, a Notary Public,
this _______ day of _______________, 20____
________________________________________
Notary Public Signature and Seal
________________________________________
As scubapete said, have this notarized. Both parents must sign the form!